Steve Harper has admitted there was a post-mortem in the Newcastle dressing room following the defeat to Bolton on Sunday.
The Magpies were booed off the St James' Park turf after once again surrendering a lead in front of the Sky cameras.
Newcastle were in total control at the interval, but defensive blunders allowed Bolton to pinch a rare win on Tyneside.
Glenn Roeder has been unable to eradicate the errors in Newcastle's backline and keeper Harper admits it is a growing cause for concern.
"We had a bit of an enquiry," said Harper. "There were a few things said which will stay in the dressing room, but they maybe needed saying.
"As good as we were in the first half, or the first 55 minutes, two minutes in the second half have cost us.
"That is three home games in a row in which we have taken the lead, only to lose it. We have dropped eight points, and it's hard to take.
"We were excellent in the first half and had we got the second goal, it might have been a different story.
"It is desperately disappointing - we have given someone two tap-ins in the middle of the goal from seven yards.
"When we are 1-0 up, maybe we are going too much for a 2-0 win. One of the things that was said in the dressing room was that we have got to learn how to win 1-0."